are you talking about frog FTK with Mass Driver or one of the other frog OTKs.
For the FTK dont hurt yourself trying to shut the frogs down just go for stopping Mass Driver. Dark Bribes, Solemn Judgement, MST, etc.

DD Crow does jack **** against good Frog FTK. They send 3 Rotoadin to grave with Swap Frog ALL THE TIME. Side 3 Hanewata, not 1 or 2. You need it your first turn because they will FTK 80% of the time. Dust, RO, MST, help if u go second only.

Crow/Crevice and (if your deck is awesome, like mine) Deck Devastation Virus. It would be good to run Hanetawa, you should. Your best chance in most situations is to draw into hanetawa initially, but crow COULD do something if you catch them off-guard (without substi-not very likely)

Also a few players misplay/cheat with the build, abusing opponents lack of frog knowledge to improve their odds. So make sure you know all the frog effects/rulings. Some of the big ones are Poison Draw Frog and Dupe Frog missing the timing, Fishborg Blaster is a "Fish" and cannot be tutored to the grave by Swap Frog who can only send LvL 2 Water and "Aqua" and Ronintoadin and Substitoad are "Toads" not "Frogs".

D.D. Crow would be a good option. Soul Release could help, as long as they don't get the OTK off first. Macro Cosmo and Dimensional Fissure could also be good options as long as they don't screw yourself over. Anything that can remove the stuff from play would work.

Also, since most of the frog OTK builds only run enough frogs to burn you to death and not any more, you could also try Barrel Behind the Door. I haven't actually seen anyone try this yet, but it could work. Black Winged Dragon could also potentially stop it.

From what I've seen, even though it's currently being called an FTK, chances are that it will take at least 2-3 turns for them to pull it off if not more. That's more then enough time to Soul Release a bunch of the stuff they need for it.